The most annoying things about wireless sensors are that most of them have batteries that need to be
replaced periodically. But what if we didn ́t need to replace batteries in the sensors lifetime? What if the
sensors could get their energy from the environment and not from a battery?
If we could have sensors that didn’t need batteries, a new series of applications would emerge, as well as
new possibilities for many industries.
This is what energy harvesting is about, that a sensor is capable of
obtaining its energy from the surroundings. For example a sensor installed inside a concert house could
gather its energy from the sound emitted by the speakers, a sensor installed in the street could gather
its energy from the pressures caused by cars passing on top of it, a sensor installed in a ceiling of a house
could get its energy from the sun, a sensor installed near a car engine could gather its energy from the
heat, a sensor installed in a water pipe could gather its energy from the water passing through it, and so
Energy Harvesting will enable new applications for all industries, for example imagine a sensor network
in a forest to monitor the behavior of selected animals.
The installation of the network will be a onetime
cost and will last several years without the need of replacing any battery. Another example is when
installing sensors in complicated or dangerous areas like a bridge; with energy harvesting there will be
only one cost related to installation and basically no cost for maintenance.
Until now a sensor can harvest its energy from light, vibrations, temperature difference, motion, sound,
radiation, radio waves and pressure.